I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
bypast bypassed biopsied
bypast past repast pst post upset psst deepest pasta paste pasty pest heppest rapist ripest ripost hippest typist papist cheapest